Several mobile data processing devices have been proposed in the last years for aiding a user to perform a number of activities. For example, so-called organizers have become very popular for specific applications; typically, these devices are used as a phone book, a calendar, an alarm clock, a scheduler, and the like.
Considering in particular the scheduler, the organizer is very useful for managing a personal agenda of a corresponding user. For this purpose, the scheduler allows the user to define different types of activities to be performed. Typical examples are tasks without specific time constraints (i.e., which may be executed at any time, generally within a defined deadline); generally, the tasks are location-dependent, that is, they must be performed at specific locations (such as an office, a shop, and the like).
Most of the schedulers known in the art provide different functions for remembering the tasks to be performed to the user. Typically, the scheduler warns the user when the deadline of each task is approaching (for example, some days before); moreover, the scheduler continues remembering the task periodically (for example, every 1-2 hours) until it has been completed.
However, the available solutions are not completely satisfactory. Indeed, the user generally forgets the tasks to be performed until the corresponding deadlines are very close (when the organizer remembers them). Moreover, it might now be difficult (if not impossible) to perform some task; a typical example is when the user is far away from the corresponding location, or when the task is remembered during a holiday period. Moreover, the user can be very busy at the moment. A worst situation arises if the user is away (for example, for a trip) and s/he is then unable to perform the task by its deadline.
All of the above is even more frustrating if the user had passed several times close to locations where the tasks were to be performed in the preceding days (without realizing that s/he could have done the tasks at that moment).
Another problem arises when the tasks require some prerequisites for their execution (such as carrying a document, having specific information available, and the like). In this case, even if the user had remembered the tasks when around their locations it would have been very unlike that s/he had all the required documents or information.
The above-described drawbacks cause a substantial waste of time for the user. Moreover, in some cases they can even result in the missing of some tasks (with the corresponding negative consequences).